﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Demo
{
    class Mianji
    {
      public int Sum(int a,int b)
        {
            return a * b;//长方形面积
        }
      public double Sum(double a)
        {
            return 3.14 * (a*a);//圆形的面积
        }
    }
}
